Abstract

Educational aims

To describe the important factors involved in the pathogenesis of bronchiectasis.

To define how a diagnosis of bronchiectasis is made.

Summary Bronchiectasis is an important cause of respiratory morbidity but one that has generally had a low profile. The prevalence of this condition varies but is common in certain indigenous populations and, anecdotally, in developing nations. It also has been recently recognised to be an ongoing problem in developed countries. As bronchiectasis is heterogeneous with a large number of predisposing factors and, generally, a long clinical history, the pathogenesis has not been well defined. The combination of a microbial insult and a defect in host defence allow the establishment of persistent bronchial infection and inflammation leading to progressive lung damage. Lung function testing usually demonstrates a mild to moderate obstructive pattern, which arises from inflammation in the small airways. There are a number of risk factors associated with this condition, which is commonly idiopathic. The microbiology of bronchiectasis is complex and changes as the disease progresses. The diagnosis is made by a combination of clinical symptoms and high-resolution computed tomography (HRCT) demonstrating abnormal airway dilatation.